This invention relates generally to a door lock assembly having an escutcheon for mounting a door lock mechanism, and more particularly to a door lock assembly having an escutcheon with removable posts for mounting a locking mechanism, including door latch and deadbolt mechanisms, on doors having different cross bore diameters.
Known door lock assemblies, including an escutcheon and a door latch, a door deadbolt, or a combination door latch and deadbolt mechanism come in different sizes, each in accordance with an industry standard that is compatible with a corresponding industry standard door cross bore diameter.
FIG. 1 illustrates an exploded view of a door and door lock assembly 101. Door 102 has two cross bores, a top cross bore 103 for a deadbolt mechanism, and bottom cross bore 104 for a latch mechanism. The diameters D103 of the cross bore 103 and D104 of the cross bore 104 can have one of a plurality of industry standard sizes. The door lock assembly 110 includes an inside escutcheon 111, an outside escutcheon 112, an inside latch handle 113 and an outside latch handle 114 for operating a latch mechanism 115, and a thumb turn 116 for operating a deadbolt mechanism 117.
When mounting the door lock assembly 110 to the door 102, it is important to properly align the inner and outer escutcheons with respect to the center axes of the cross bores and with respect to the vertical and backset positions of the latch and deadbolt mechanisms. Accordingly, conventional door lock assemblies have been designed to fit one standard cross bore size, requiring multiple designs to cover the various industry standard cross bore sizes. This has led to an increase in the manufacturing and stocking costs for door lock assemblies.
U.S. Pat. No. 4,671,089 discloses a door latch and deadbolt assembly aimed at facilitating the assembly""s mounting to doors having different cross bore diameters. Specifically, referring to FIG. 1, this patent discloses a combination door latch and deadbolt assembly 110 including an escutcheon 111, 112 with breakaway tabs 118 for mounting the escutcheon to doors having different standard cross bore diameters. When left on the escutcheon upon installation, the breakaway tabs allow the escutcheon to be snugly mounted to a door having a cross bore with a first diameter. However, when the breakaway tabs are broken off from the escutcheon, the escutcheon can be snugly mounted to a door having a cross bore with a second diameter that is larger than the first diameter.
The breakaway tabs disclosed in U.S. Pat. No. 4,671,089 are formed as protrusions that are integrally molded to the inner face of the escutcheon, so that they can be removed only by breaking (i.e., permanently severing) the tabs from the escutcheon. The patent teaches that this frangibility of the tabs is an important feature, since it allows the escutcheon to be quickly adapted to a larger cross bore size by breaking off one or more tabs. However, since removal of the tabs results in the permanent alteration of the structure of the escutcheon, once the tabs are broken, it is impossible to re-adapt this escutcheon to fit a cross bore having a smaller diameter. Therefore, any mistake in sizing the escutcheon to the cross bore will result in the need to purchase a new escutcheon or door lock assembly.
A further problem encountered in known door latch assemblies involves assembling the latch mechanism to the escutcheon. For example, U.S. Pat. No. 4,671,089 discloses a latch mechanism design in which the latch socket (also referred to as a bushing) is inserted into a through-hole in the escutcheon for the latch mechanism from the outward facing side of the escutcheon, and held in place prior to attachment of the latch handle by a retainer ring (also referred to as a circular clip) attached to the socket from the inward-facing side of the escutcheon. Accordingly, the assembly process is cumbersome, requiring the additional handling and fixing of the retainer ring.
This invention is directed to overcoming one or more of the problems that is set forth above.
According to the present invention a door lock assembly is provided that includes an escutcheon and a door latch and deadbolt mechanism having diametrically opposed post mounts, preferably with threaded holes, each post mount coupled to a removable post such as a headless screw so as to be removable without permanent alteration to the escutcheon. The combination post mounts and removable posts provides a mechanism that allows onsite modification of the escutcheon for mounting the escutcheon on doors having different cross bore diameters. In particular, this combination provides a two-way modification of the door lock assembly to adapt to a door with a small cross bore, and to readapt the assembly to a door with a large cross bore without permanently altering the assembly.
According to another embodiment of the present invention, a door lock assembly is provided with an escutcheon assembly having a plate with a through-hole for mounting, and a latch mechanism partially inserted in the through-hole with a handle for operating the latch mechanism. The latch mechanism further includes a bushing having a drive head for coupling to the handle so as to rotate with the handle, an abutment portion spaced from a distal end of the drive head, and an ear protruding from a portion of the bushing intermediate to the distal end of the drive head and the abutment portion. The plate with the through-hole further includes an opening communicating with the through-hole for receiving the ear of the bushing when the bushing is inserted in the through-hole. Accordingly, when the ear is passed through the opening and the bushing is rotated, the ear slidably engages an outside of the through-hole to prevent axial removal of the bushing. This combination, therefore, provides a latch mechanism that can be easily assembled to the escutcheon without the need for an extra part such as a circular clip to axially secure the bushing of the latch mechanism to the escutcheon.